Rulebook: Part Three

I Call It Luck

By Michael Mikaelian

This spring, SW:TCG will see the release of Revenge of the Sith -- and with it, a new rulebook. Michael Mikaelian continues his coverage of exactly what this rulebook will contain, what's been added, what's been changed -- this time looking at the Lucky mechanic.

While Henry Stern, Wizards of the Coast R&D lead developer for the Star Wars TCG, had a list of topics he wanted the Star Wars Guru discussion group members to tackle for the Revenge of the Sith rulebook, those topics weren’t the only things discussed by the group. One topic pondered deeply—some felt a little too deeply—was the Lucky ability.

Not All Luck is Good

Currently, Lucky X is defined as: “Each attack, you may reroll X of this unit’s attack dice, or have your opponent reroll X attack dice against it.” The #1 detail that escaped many players reading this ability for the first time was its lack of the words “up to.” Without that modifying phrase, there’s the potential for some unpleasant situations. A unit with Lucky 2 or greater must reroll that many dice if the player chooses to use the Lucky ability. Choosing to reroll fewer dice is not an option.

For example, Anakin Skywalker (J)’s Pilot ability that gives his unit Lucky 2 is great—when the Dark Side rolls two or more hits against Anakin’s unit. When a Dark Side unit rolls multiple dice and only scores one hit, now the Light Side has a lot of thinking to do. Does the Light Side player use Lucky to reroll two dice from the attack—a hit and a miss—or just take the hit?

If an attacking unit has Critical Hit, Accuracy, or some other nasty attack-related ability, using Lucky to reroll a hit and a miss could increase the damage. Is this really in the spirit of the Lucky ability? While the Star Wars Guru group didn’t think so, there was some concern about how adding “up to” would make this already useful ability too good. A unit with multiple Lucky abilities could reroll the same die twice, not reroll any misses, and would never be forced to reroll hits.

Processing… Processing…

Statistically speaking, Lucky is good. It turns a 50% chance of a single die rolling a hit into a 75% chance of success. That’s if it’s used only once on that die. Two Lucky abilities influencing the same die increase the chance of success to 83%. And that’s only if the attacking unit doesn’t have Accuracy. Defensively, the odds are inverted: one roll yields a hit 50% of the time; two, 25% of the time; and three, 17% of the time. Against a unit with Armor and two Lucky abilities, the chances of hitting are almost nonexistent.

The group slung around a lot of math to support all of this. Here are some examples of what they were subjected to in the name of research.

Chances of a Lucky unit hitting with a single die roll, by method:

Type of Roll

X+Y (one reroll)

X then Y (two rerolls)

Accuracy 0 (normal attack)

75.00%

87.50%

Accuracy 1

88.90%

96.30%

Accuracy –1 (or vs. Armor)

55.60%

70.40%

Natural 6 (reroll any result)

30.60%

42.10%

(reroll misses only)

25.00%

29.20

X+Yh/6 + (h/6*m/6)

X then Yh/6 + (h/6*m/6) + (h/6*m/6*m/6)

h = number of different possible hit resultsm = number of different possible miss results

The X-Y Debate

The working term for using one Lucky ability, seeing the results, and then using a second Lucky ability was dubbed the “X then Y” method. “X then Y” seemed quite powerful in theory, and had the advantage of being the way it’s currently done. Another proposed method, “X+Y,” called for all of a unit’s Lucky abilities to combine into one Lucky value. Such a unit can only use Lucky once per attack, and each increment of Lucky can only affect a different die.

“X then Y” gives low-power Lucky units incredible punch. They’re not quite Accuracy 3 units, but they might as well be. One thing Lucky can do that Accuracy can’t is give the player extra chances to trigger a Critical Hit. “X then Y” excels at this. Rerolling the same die twice in hopes of a Critical Hit increases the odds from 17% to 31% of the reroll coming up a 6. “X then Y” also outperforms Armor when defending against low-power units. Armor protects against damage 66% of the time. If every attack die is covered by Lucky, it protects 75% of the time. If each die is double covered, say hello to 83% protection. “X then Y” doesn’t perform nearly as well when used with greater power values, but low-powered units are far more common in Star Wars TCG.

“X+Y” puts a limit on this odds stacking. In order for this method to work, however, Lucky must include the phrase “up to.” If it doesn’t, the ability becomes even more counterintuitive: You’d rather have a Lucky 2 Pilot on a Space unit than one with Lucky 1. Together, you could only reroll three dice, not two or one.

After the first table comparing “X then Y” to “X+Y” circulated, Henry let us know not to worry too much about it. It was pretty clear that “X+Y” was preferable. Starting with the release of Revenge of the Sith, Lucky will read: “Each attack, you may reroll up to X of this unit’s attack dice or have your opponent reroll up to X attack dice against it.” The glossary also makes it clear that you add all of a unit’s Lucky abilities together before rerolling any attack dice.

What About Bad Luck?

Another idea that came up was the concept of a negative Lucky value. Greedo (B) has Accuracy –1, why not define what Lucky –X would mean while there’s a chance to get it into a rulebook? In essence, Lucky –X would give the other player’s unit Lucky X when the “Unlucky” unit was attacking or defending. This seemed like a perfect ability for Greedo or a version of Boba Fett based on his last film encounter with Han Solo. Despite its potential as a space saver, however, Lucky –X does not appear in the Revenge of the Sith rulebook.

Noodling how Lucky should be played was just a warm-up for our next topic: turn order.

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